Fluorinated ion-exchange polymers and intermediates therefor

ABSTRACT

Disclosed herein are partially fluorinated (co)polymers containing sulfonic acid or sulfonate salt groups, processes for making those polymers, and intermediates for those (co)polymers. The (co)polymers are useful as ion-exchange resins and (in the sulfonic acid form) acid catalysts.

This is a continuation-in-part of Ser. No. 08/388,789, filed Feb. 15,1995 now U.S. Pat. No. 5,475,143.

FIELD OF THE INVENTION

This invention concerns partially fluorinated sulfonic acid containingpolymers suitable as ion-exchange resins and strong acid catalysts, andnovel intermediates thereto.

TECHNICAL BACKGROUND

Polymers containing strongly acidic or basic groups are useful asion-exchange resins, and for other uses. Sulfonic acid containingpolymers are useful as ion-exchange resins and as strong acid catalysts.Polymers which are fluorinated may also be more thermally and/orchemically resistant than unfluorinated polymers, so fluorinatedsulfonic acid containing polymers may be particularly useful. Suchpolymers are useful in the form of films, coatings, membranes, othershaped articles and particles.

For use as an ion exchange resin or strong acid catalyst resin, it isgenerally preferred if the resin contains as many active sites aspossible. It is known in the art (see, for instance, U.S. Pat. No.4,948,844) that it is difficult to (co)polymerize perfluorinated (alkylvinyl ethers), while fluorinated alkyl vinyl ethers which contain somehydrogen in the alkyl group, particularly alpha to the ether oxygen, aremore readily polymerizable, and can be (co)polymerized to give polymerswith high vinyl ether contents.

Yu. E. Kirsh, et al., Russian Chemical Rev., vol. 59, p. 560-574 (1990)have reviewed the literature of perfluorinated cation exchangemembranes.

U.S. Pat. No. 4,597,913 describes the synthesis of certainperfluorinated (with the exception of the "R" group on the sulfur)sulfide containing vinyl ethers, (co)polymers containing those vinylethers as repeat units, and oxidation of the (co)polymers to obtain theanalogous sulfonic acid containing perfluorinated polymers. No mentionis made of partially fluorinated sulfonic acid containing polymers.

T. Nguyen, et al., Eur. Polym. J., vol. 27, p. 435-438 (1991) describethe preparation of certain perfluorinated (with the exception of the "R"group on sulfur) sulfide containing vinyl ethers and their conversion tosulfonyl chlorides. No mention is made of the novel compounds describedherein.

SUMMARY OF THE INVENTION

This invention concerns a copolymer consisting essentially of the repeatunits ##STR1## wherein: Q is --SO₃ M, --SCl, --SO₂ Cl or --SR¹ ;

n is an integer of 1 to 10;

M is hydrogen, an alkali metal cation or an ammonium ion; and

R¹ is an alkyl group containing 1 to 10 carbon atoms;

and provided that the molar ratio of (I):(II) is 0:100 to about 99:1.

This invention also provides a compound of the formula

    CF.sub.2 ═CFOCH.sub.2 CF.sub.2 (CF.sub.2).sub.n SR.sup.1 (V)

wherein R¹ is an alkyl group containing 1 to 10 carbon atoms; and n isan integer of 1 to 10.

Also disclosed herein is a process to make a partially fluorinatedpolymer, comprising:

reacting tetrafluoroethylene, carbon dioxide, and an alkali metalthioalkoxide to obtain the alkali metal salt of a thio-containingpartially fluorinated alkali metal carboxylate, and reacting saidcarboxylate with a dialkyl sulfate to obtain an ester of athio-containing partially fluorinated carboxylic acid; or

reacting tetrafluoroethylene, an alkali metal thioalkoxide and a dialkylcarbonate to obtain said ester;

reducing said ester with a suitable reducing agent to the correspondingthio-containing partially fluorinated alcohol;

reacting said alcohol with a base capable of forming an alkoxide anionfrom said alcohol, and tetrafluoroethylene, to form a monomer of theformula CF₂ ═CFOCH₂ CF₂ CF₂ SR¹ ;

free radically polymerizing said monomer, optionally withtetrafluoroethylene comonomer, to form a thio-containing polymer;

reacting said thio-containing polymer with a sufficient amount ofchlorine at a temperature of about 80° C. to about 140° C. for a periodof time sufficient to form a sulfenyl chloride containing polymer; and

reacting said sulfenyl chloride containing polymer with a sufficientamount of chlorine and water, at a temperature of about 80° C. to about140° C., for a period of time sufficient to form a sulfonyl chloridecontaining polymer; and

converting said sulfonyl chloride containing polymer to a sulfonic acid,alkali metal sulfonate, or ammonium sulfonate by reaction with water, analkali metal base or an amine, respectively;

and wherein R¹ is alkyl containing 1 to 10 carbon atoms.

Described herein is a process for producing a sulfonyl chloride orsulfonic acid containing polymer, comprising,

(a) contacting at 80° C. to about 140° C., a sufficient amount ofchlorine with a polymer consisting essentially of the repeat units##STR2## for a period of time sufficient to produce a polymer consistingessentially of the repeat units ##STR3##

(b) contacting at 80° C. to about 140° C., a sufficient amount ofchlorine and water with a polymer consisting essentially of repeat units(I) and (IV) for a period of time sufficient to produce a polymerconsisting essentially of the repeat units ##STR4## or carrying (a) and(b) simultaneously on a polymer consisting essentially of repeat units(I) and (III) to produce a polymer consisting essentially of repeatunits (I) and (VI);

wherein n is an integer of 1 to 10; R¹ is an alkyl group containing 1 to10 carbon atoms; and T is SO₂ Cl or SO₃ H;

and provided that the molar ratio of (I):(III) is 0:100 to about 99:1.

DETAILS OF THE INVENTION

The synthesis of the final partially fluorinated sulfonic acid (orsulfonate) containing polymers described herein can be done by a seriesof reactions. Some of these reactions are known. For instance thefollowing reactions would be applicable when n is >1.

    R.sup.1 SNa+I(CF.sub.2).sub.n I→R.sup.1 S(CF.sub.2).sub.n I(A)

    R.sup.1 S(CF.sub.2).sub.n I+H.sub.2 C═CH.sub.2 →R.sup.1 S(CF.sub.2).sub.n CH.sub.2 CH.sub.2 I                     (B)

    R.sup.1 S(CF.sub.2).sub.n CH.sub.2 CH.sub.2 I→R.sup.1 S(CF.sub.2).sub.n CH═CH.sub.2                         (C)

    R.sup.1 S(CF.sub.2).sub.n CH═CH.sub.2 →R.sup.1 S(CF.sub.2).sub.n COOH                                                      (D)

    R.sup.1 S(CF.sub.2).sub.n COOH→R.sup.1 S(CF.sub.2).sub.n CH.sub.2 OH (E)

Once the product of E is obtained, the synthesis can proceed similarlyto that shown in (5a) and (5b), below. The following papers containinformation on the above reactions:

(A) C. Wakselman, et al., in "Organofluorine Chemistry. Principles andCommercial Applications", R. E. Banks, et al., (ed.), Plenum Press, NewYork, 1994, p. 182.

(B) and (C) Ibid., p. 189.

(D) M. Hudlicky, "Chemistry of Organic Fluorine Compounds", EllisHorwood, Ltd., 1976, p. 210, using potassium permanganate as theoxidant.

(E) Ibid., p. 180, using LiAlH₄ or NaBH₄ as the reducing agents.

One method to obtain the vinyl ether monomer (V) is to first prepare analcohol of the formula HOCH₂ CF₂ (CF₂)_(n) SR¹ (VI), wherein n and R¹are as defined above. For instance, when n is 1, (VI) can be obtained byeither of the following reaction sequences:

    R.sup.1 SNa+CF.sub.2 ═CF.sub.2 +CO.sub.2 →R.sup.1 SCF.sub.2 CF.sub.2 CO.sub.2 Na                                      (1)

    R.sup.1 SCF.sub.2 CF.sub.2 CO.sub.2 Na+(R.sup.2 O).sub.2 SO.sub.2 →R.sup.1 SCF.sub.2 CF.sub.2 CO.sub.2 R.sup.2       ( 2)

    or

    R.sup.1 SNa+CF.sub.2 ═CF.sub.2 +(R.sup.2 O).sub.2 C═O→R.sup.1 SCF.sub.2 CF.sub.2 CO.sub.2 R.sup.2( 3)

    then

    R.sup.1 SCF.sub.2 CF.sub.2 CO.sub.2 R.sup.2 +NaBH.sub.4 →R.sup.1 SCF.sub.2 CF.sub.2 CH.sub.2 OH                            (4)

Reactions similar to (1) and (2) are described in U.S. Pat. No.4,474,700, col. 4, line 67 to col. 5, line 3 (which is hereby includedby reference), while reactions similar to (3) are described in U.S. Pat.Nos. 4,597,913 and 4,555,369 (which are hereby included by reference).While not critical, reaction (3) may be carried out at about 0° C. toabout 100° C., and reaction (4) at about 0° C. to about 50° C. The samesolvents for (1) and (2), as recited in U.S. Pat. No. 4,474,700 may beused for (3). For (4), it is preferred to run the reaction in water or alower alcohol, such as ethanol, or a mixture of the two. In reaction (4)alkali metal borohydrides are suitable reducing agents, but LiAlH₄ orhydrogen in the presence of a suitable catalyst may also be used underconditions known to the artisan.

The alcohol formed in reaction (4) may be converted to the vinyl etherby

    R.sup.1 SCF.sub.2 CF.sub.2 CH.sub.2 OH+NaH→R.sup.1 SCF.sub.2 CF.sub.2 CH.sub.2 O--Na.sup.+                             ( 5a)

    R.sup.1 SCF.sub.2 CF.sub.2 CH.sub.2 O--Na.sup.+ +CF.sub.2 ═CF.sub.2 →R.sup.1 SCF.sub.2 CF.sub.2 CH.sub.2 OCF═CF.sub.2 ( 5b)

Reactions (5a) and (5b) may be carried out in sequence in a singlereactor. Any suitable base that will produce the appropriate alkoxideanion in a reaction such as (5a) may be used, such as an alkali metalhydride or metal alkyl. Reaction (5a) may be carried out at atemperature of about 0° C. to about 50° C., which reaction (5 b) can becarried out at about 25° C. to about 100° C. The pressure range andsolvents which are useful for (5b) include those listed in U.S. Pat. No.4,474,700, supra. Dioxane is also a useful solvent.

Compounds of formula (V), such as the product of reaction (5b) may behomopolymerized or copolymerized with TFE, using standard free radicalpolymerization techniques, see for instance U.S. Pat. Nos. 4,273,728,4,273,729 and 4,275,225, which are hereby included by reference. Thepolymerizations may be conducted neat, in the presence of an organicliquid (which may or may not be solvent for any of the startingmaterials and/or product polymer, and which preferably does not causeappreciable chain transfer), or in aqueous suspension or emulsion. Forinstance, a polymerization may be run in 1,1,2-trichlorotrifluoroethaneusing perfluoropropionyl peroxide as the free radical initiator.Polymerization temperature is chosen depending on the type of initiatorand is generally in the range of 0° C. to about 150° C. Preferredtemperatures are from about 25° C. to about 100° C. Polymerizations aregenerally run in a closed pressure vessel so as to minimize loss ofvolatile or gaseous monomers, in the absence of oxygen and at autogenouspressures.

The (co)polymer produced by the (co)polymerization of (V) is soluble inorganic solvents, and so is useful as a chemically resistant coating orencapsulant. The coating may be made by applying the solution to thesurface to be coated by brushing, spraying or rolling etc., of asolution of the polymer, and the solvent allowed to evaporate. Anarticle may be encapsulated by dipping or otherwise completely coatingthe article with a polymer solution and allowing the solvent toevaporate.

The (co)polymers of (V) are also useful as intermediates for thepreparation of a sulfonic acid containing (co)polymer which is useful asan ion-exchange resin or an acid catalyst. The sulfonic acid is producedby oxidation of thio group present in the (co)polymer. When thisoxidation is carried out it is important that the reactions used toproduce the sulfonic acid group are selective so that the --CH₂ -- groupin the polymer is not oxidized or otherwise chemically changed. This issomewhat different from the analogous thio-containing perfluorinatedpolymers, which are overall much more resistant to such oxidations orother side reactions.

Continuing with the polymer of the product of reaction (5b), thisoxidation may be accomplished by the following reactions (only theappropriate sulfur group is shown on the polymer--the remainder of thepolymer is chemically unaffected)

    --CH.sub.2 CF.sub.2 CF.sub.2 SR.sup.1 +Cl.sub.2 →--CH.sub.2 CF.sub.2 CF.sub.2 SCl                                              (6a)

    --CH.sub.2 CF.sub.2 CF.sub.2 SCl+Cl.sub.2 +H.sub.2 O→--CH.sub.2 CF.sub.2 CF.sub.2 SO.sub.2 Cl                             (6b)

    --CH.sub.2 CF.sub.2 CF.sub.2 SO.sub.2 Cl+H.sub.2 O→--CH.sub.2 CF.sub.2 CF.sub.2 SO.sub.3 H                              (6c)

The product of reaction (6c) may be converted to an alkali metal orammonium sulfonate by reaction with an appropriate base, such as sodiumhydroxide, potassium carbonate, or ammonium hydroxide.

For reaction (6a) the minimum amount of chlorine desired is thestoichiometric amount, but it is preferred if there is a 2 to 5 foldexcess of chlorine present. For reaction (6b) it is desirable to have atleast the stoichiometric amounts of water and chlorine present, but itis preferred if the water is present in 2 to 20 fold excess, and thechlorine is present in 2 to 5 fold excess. Reaction (6b) may also beconducted in the presence of an organic acid, such as acetic acid ortrifluoroacetic acid, or in an inert organic solvent such as1,1,2-trichloro-1,2,2-trifluoroethane. Reaction (6a) and (6b) arepreferably done is a closed pressure vessel so as to minimize the lossof volatile reagents, and under autogenous pressure. Reaction (6b) ispreferably done is a vessel constructed of glass or an inert polymericmaterial such as polytetrafluoroethylene, to minimize formation ofcorrosion products which may be foraged in metal reactors. In bothreactions, having at least a stoichiometric amount of each reagentpresent ensures at least the possibility that all of the thio groupswill be converted to sulfonyl chloride groups.

For reaction (6c), typical hydrolysis conditions for sulfonyl chloridesare used, which involves contact of the sulfonyl chloride with water anda base such as sodium, potassium or ammonium hydroxide. Ambienttemperatures are convenient, although temperatures up to 75° C. may beused to accelerate the hydrolysis reaction. If sufficient base is usedto form the sulfonate salt, the sulfonic acid may be may be made byaddition of a strong acid.

The resulting sulfonyl chloride containing polymer consists essentiallyof repeat unit repeat unit (IV), and optionally repeat unit (I). Thepolymer wherein corresponding unit is a sulfonic acid or sulfonate groupconsists essentially of the repeat unit (II), and optionally repeat unit(I). In both instances "consisting essentially of" includes polymerswith small amounts of residual (unconverted) thio, sulfenyl chloride,and/or sulfonyl chloride groups.

In some preferred polymers containing repeat unit (II), repeat unit (I)is also present. In these polymers it is preferred that the molar ratioof (I):(II) in the polymer is about 1:99 to about 99:1, more preferablyabout 1:10 to about 10:1. In another preferred polymer, the ration of(I):(II) is 0:100.

In all of the compounds and polymers herein, as applicable: it ispreferred that all alkyl or substituted alkyl groups contain 1 to 10carbon atoms, and more preferred if such alkyl groups are methyl groups;it is also preferred if R¹ is alkyl, especially methyl; and it ispreferred if n is 1.

EXAMPLE 1 Synthesis of CH₃ SCF₂ CF₂ CO₂ CH₃

A 400 mL pressure vessel was charged with 34.1 g (0.49 mol) of sodiumthiomethoxide and 150 mL of anhydrous dimethylsulfoxide (DMSO). Thevessel was closed, cooled in dry ice, evacuated and charged with 32 g(0.73 mol) of carbon dioxide and 50 g (0.5 mol) of tetrafluoroethylene.The vessel contents were heated with agitation to 50° C. for 1 hr and100° C. for 5 hr. After cooling to room temperature, the vessel contentswere transferred to a 500 mL round bottom flask using an additional 30mL of DMSO to rinse. Dimethylsulfate (65 g, 0.52 mol) was added and themixture was stirred for 3 hr at 30°-50° C. Volatiles were removed bydistillation at 1 mm into a dry ice cooled receiver with a maximum pottemperature of 65 ° C.

The volatiles collected from eight reactions were combined, washed withwater and dried over anhydrous magnesium sulfate. Distillation throughan 18 inch Vigreaux column gave 547 g (80% ) of colorless liquid, bp 88°C. at 60 mm. ¹ H NMR (δ, CDCl₃) 2.38 (s, 3H), 3.96 (s, 3H); ¹⁹ F NMR (δ,CDCl₃) -92.5 (t, 2F), -117.0 (t, 2F).

EXAMPLE 2 Synthesis of CH₃ SCF₂ CF₂ CH₂ OH

The ester CH₃ SCF₂ CF₂ CO₂ CH₃ (546 g, 2.65 mol) was added dropwise over3 hr to a solution of 100.2 g (2.65 mol) of sodium borohydride in 920 mLof ethanol which was cooled in an ice water bath. After the addition wascomplete the mixture was allowed to warm to room temperature over 1 hr.The mixture was cooled in ice water and cautiously hydrolyzed byaddition of 1.4 L of 6N hydrochloric acid. The mixture was diluted to5-L with water and a lower layer was collected. The aqueous solution wasextracted with 500 mL of methylene chloride. The organic layers werewashed with 1-L of water and dried over anhydrous magnesium sulfate. Themethylene chloride was removed by distillation at atmospheric pressurethrough an 18 inch Vigreaux column. Distillation of the residue throughthe same column gave 372.5 g (79 %) of colorless liquid, bp 35°-38° C.at 0.15 mm. .sup. 1 H NMR (δ, CDCl₃) 2.58 (s, 3H), 2.88 (t, 1H), 4.05(m, 2H); ¹⁹ F NMR (δ, CDCl₃) -92.7 (t, 2F), -121.7 (m 2F).

EXAMPLE 3 Synthesis of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂

The alcohol CH₃ SCF₂ CF₂ CH₂ OH (53.4 g, 0.3 mol) was added dropwise toa suspension of 8.75 g of 95% sodium hydride in 100 mL of anhydrousdioxane which was cooled in an ice water bath. This mixture was stirredovernight at room temperature and transferred to a 400 mL stainlesssteel pressure vessel using an additional 40 mL of dioxane to rinse. Thevessel was closed, cooled in dry ice, evacuated, charged with 50 g oftetrafluoroethylene, warmed to 50° C. and agitated for 18 hr. The vesselwas vented to atmospheric pressure at room temperature and its contentswere poured into 1 L of ice water containing 25 mL of concentratedhydrochloric acid. The lower layer was separated and washed with 500 mLof ice water.

The combined product from seven runs was washed again with 2×500 mL ofice water and distilled through a 16 inch Vigreaux column. A liquidweighing 371 g was collected with a boiling point of 50°-52° C. at 20-25mm. This product in two portions was chromatographed through columns of1 Kg silica gel, packed in pentane. The columns were eluted withpentane. Early fractions which contained only the desired product byglpc analysis were combined and distilled through the Vigreaux column atatmospheric pressure to remove the solvent and then at reduced pressureto give 291.8 g of product, bp 54°-55° C. at 26 mm which was a minimumof 99.5% pure by glpc analysis. An additional 51 g of product which was95% pure by glpc analysis was obtained from latter chromatography cuts.¹ H NMR (δ, CDCl₃) 2.39 (s, 3H), 4.38 (t, 2H); ¹⁹ F NMR (δ, CDCl₃) -92.6(s, 2F), -120.1 (m 2F), -121.8 (dd, 1F), -127.5 (dd, 1F), -137.0 (dd,1F). Another sample prepared in the same fashion was submitted forelemental analysis.

Anal. Calcd. for C₆ H₅ F₇ OS: C, 27.91; H, 1.95; F, 51.52; S, 12.43.Found: C, 27.89; H, 2.04; F, 52.32; S, 12.34.

EXAMPLE 4 Polymerization of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂

A 50 mL round bottom flask was charged with 5.8 g of CH₃ SCF₂ CF₂ CH₂OCF═CF₂ and 10 g of 1,1,2-trichlorotrifluoroethane. This solution wasfrozen, and the reactor vessel was evacuated and filled with argonseveral times. A solution (1.0 mL) of about 0.025M (CF₃ CF₂ CF₂OCF(CF₃)CO₂)₂ in CF₃ CF₂ CF₂ OCFHCF₃ was added at -30° C. The solutionwas allowed to slowly warm to room temperature and stirred for 72 hr. Itwas poured into 300 mL of hexane which was cooled in dry ice. The hexanewas decanted from the solid polymer which was dried in a vacuum oven at125° C. to give 4.3 g of clear glass. DSC analysis showed a Tg at about14° C. on the second heat and no melting peak.

EXAMPLE 5 Copolymerization of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂ andTetrafluoroethylene in a 1:2 Molar Ratio

An 80 mL pressure vessel was cooled in dry ice and charged with 19 g ofCH₃ SCF₂ CF₂ CH₂ OCF═CF₂, 44 g of 1,1,2-trichlorotrifluoroethane and 10mL of a solution of about 0.025M (CF₃ CF₂ CF₂ OCF(CF₃)CO₂)₂ in CF₃ CF₂CF₂ OCFHCF₃. The tube was closed, evacuated and charged with 15 g oftetrafluoroethylene. The tube was allowed to warm without externalheating. Internal pressure reached a maximum of about 1 MPa at 19° C.and fell over the course of several hours to 0.2 MPa at 26° C. Thereactor was vented to atmospheric pressure and a thick clear gel in thereactor was dissolved in about 800 mL of 1,1,2-trichlorotrifluoroethane.This solution was filtered, concentrated to about 500 mL and addedslowly to 800 mL of hexane which was cooled in dry ice. The solidprecipitate was collected, dried under a heat lamp and then in a vacuumoven at 125° C. to give 27.3 g of white polymer which could be pressedat 80° C. to a clear tough film. Inherent viscosity in1,1,2-trichlorotrifluoroethane was 0.24 dl/g. ¹ H NMR (δ, CCl₂ FCClF₂)2.35 (s, 3H), 4.42 (t, 2H); ¹⁹ F NMR (δ, CDCl₃) -92.9 (s, CF₂ S), -135to -137.5 (tertiary F), -117 to -122.5 (CF₂ groups). By integration ofabsorptions at -92.9 and -135 to -137.5 versus the other absorptions,the ratio of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂ to tetrafluoroethylene in thepolymer was 1 to 1.82. DSC analysis showed a T_(g) at 5.4° C. on thesecond heat and no melting peak. Another polymer sample prepared insimilar fashion using perfluoropropionyl peroxide as initiator had aninherent viscosity of 0.197 and about a 1:2 ratio of monomers ascalculated from its ¹⁹ F NMR spectrum.

Anal. Calc. for 1:2 copolymer: C, 26.21; H, 1.10; F, 62.20; S, 6.99.Found: C, 25.67; H, 1.15, F, 61.91; S, 6.94.

A third sample of this copolymer was prepared using 29 g of1,1,2-trichlorotrifluoroethane and 5 mL of the 0.025M (CF₃ CF₂ CF₂OCF(CF₃)CO₂)₂ in CF₃ CF₂ CF₂ OCFHCF₃ initiator solution. This materialhad an inherent viscosity of 0.30 dL/g.

EXAMPLE 6 Copolymerization of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂ andTetrafluoroethylene in a 1:4 Molar Ratio

Following the procedure of Example 5, a mixture of 14.5 g CH₃ SCF₂ CF₂CH₂ OCF═CF₂, 5 mL of a solution of about 0.025M (CF₃ CF₂ CF₂OCF(CF₃)CO₂)₂ in CF₃ CF₂ CF₂ OCFHCF₃ and 23 g of tetrafluoroethylene wasallowed to react for about 13 hr at a maximum temperature of 28° C. Theresulting gel was washed several times with1,1,2-trichlorotrifluoroethane and dried at 120° C. in a vacuum oven togive 26.5 g of a colorless solid polymer which could be pressed to aclear film at 225° C. DSC analysis showed no thermal events from 0° to350° C. on the second heating. The polymer was determined to contain82.3 mole % of tetrafluoroethylene and 17.7 mole % of the sulfurcontaining comonomer by integration of appropriate resonances in itsfluorine NMR spectrum, measured in hexafluorobenzene solution at 80° C.

EXAMPLE 7 Conversion of the --CF₂ SCH₃ Side Chain to --CF₂ SCl

A 2.9 g sample of polymer from Example 5 was dissolved in 50 mL of1,1,2-trichlorotrifluoroethane in a heavy walled glass tube. The tubecontents were frozen and the tube was evacuated, charged with 3.5 mL ofliquid chlorine and sealed. The tube was heated in an oven at 120° C.for 14 hr. It was cooled in dry ice and acetone, opened and the clearsolution was concentrated under vacuum at 40° C. to a white opaquesolid. A proton NMR spectrum of the solid in1,1,2-trichlorotrifluoroethane showed the presence of a triplet at 4.46ppm for the pendant OCH₂ group and the nearly complete absence of theSCH₃ signal at 2.35 ppm.

EXAMPLE 8

Conversion of the --CF₂ SCl Side Chain to --CF₂ SO₂ Cl

The product from Example 7 in 50 mL of 1,1,2-trichlorotrifluoroethanewas sealed into a heavy-walled glass tube with 20 mL of water and 4 mLof liquid chlorine. The tube was heated in an oven at 100° C. for 16 hrand at 120° C. for 16 hr. The organic layer was isolated andconcentrated under vacuum to 2.87 g of light yellow solid. An infraredspectrum of the solid showed a band at 1421 cm⁻¹ suggesting the presenceof the CF₂ SO₂ Cl group.

EXAMPLE 9 Copolymerization of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂ andTetrafluoroethylene

An 80-mL Hastelloy® pressure vessel was cooled in dry ice, flushed withargon and charged with 19.3 g of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂, 29 g of1,1,2-trichlorotrifluoroethane and 1-ml of and approximately 0.025Msolution of (CF₃ CF₂ CF₂ OCF(CF₃)CO₂)₂ in CF₃ CF₂ CF₂ OCHFCF₃. Thevessel was closed, evacuated and charged with 15 g oftetrafluoroethylene. The vessel was agitated while being allowed to warmto room temperature overnight. The vessel was vented, the contents werediluted with additional 1,1,2-trichlorotrifluoroethane, filtered andconcentrated in vacuum to 8.03 g of solid polymer. The polymer wasdissolved in 1,1,2-trichlorotrifluoroethane and poured slowly intopentane which was chilled to -40° C. The solid polymer was isolated anddried under vacuum affording 7.36 g of polymer with an inherentviscosity (1,1,2-trichlorotrifluoroethane) of 0.48 dL/g. Its proton andfluorine NMR spectra were as described in Example 5 and the molar ratioof CH₃ SCF₂ CF₂ CH₂ OCF═CF₂ to tetrafluoroethylene units in the polymerwas calculated as 2:3.

EXAMPLE 10 Polymerization of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂

A 50-mL round bottom flask was charged with 10.3 g of the title monomerand evacuated and filled with argon four times. The flask was cooled ina dry ice bath and 1 mL of a solution of about 0.035M (CF₃ CF₂ CF₂OCF(CF₃)CO₂)₂ in CF₃ CF₂ CF₂ OCHFCF₃ was added. This solution wasallowed to stir for 48 hr at 0° C., warmed over one day to roomtemperature, stirred for one day at room temperature and warmed to 50°C. for 3 hr. It was cooled to -5° C. and a second 1-mL portion of theperoxide initiator solution was added. This mixture was allowed to warmto room temperature over 1 day and heated to 50° C. for 3 hr. Theproduct was dissolved in tetrahydrofuran (THF) and precipitated byadding to 500 mL of pentane which had been cooled to -40° C. The freelydivided solid was collected, dissolved in THF and evaporated undervacuum giving 6.23 g of polymer. Inherent viscosity in THF was 0.19dl/g. Analysis by gel permeation chromatography in THF showed M_(n)=34300 and M_(w) =94300 versus poly(methyl methacrylate) standards. AnM_(w) of 94300 g/mol was measured by laser light scattering in toluenesolution. ¹ H NMR (δ, THF-D₈) 2.4 (3H), 4.5 (2H). ¹⁹ F NMR (δ, THF-D₈)-92.1 (2F, CF₂ S), -109 to -119 (2F, backbone CF₂), -119.1 (2F, CH₂CF₂), -130 to -133.5 (1F).

EXAMPLE 11 Emulsion Homopolymerization of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂

A 1-L round bottom flask was swept with argon and charged with 200 mL ofdeoxygenated water, 1.9 g of ammonium perfluorononanoate, 12.9 g of thetitle monomer and 2 g of Na₂ HPO₄ •7H₂ O. This mixture was stirredvigorously at room temperature and 0.052 g of sodium bisulfite and 0.057g of ammonium persulfate were added. This mixture was stirred for 24 hrat room temperature. An additional 0.052 g of sodium bisulfite and 0.057g of ammonium persulfate were added and this mixture was stirred for 24hr at room temperature. The emulsion was diluted with 200 mL ofdistilled water and frozen in dry ice. After thawing, the mixture wasfaltered and the solid was washed with 2×500 mL of water and dried undervacuum giving 11.8 g of white solid polymer. Inherent viscosity in THFwas 0.069 dL/g and the proton and fluorine NMR spectra were as describedin Example 10.

EXAMPLE 12 Conversion of the --SCH₃ Group to --SCl in the CH₃ SCF₂ CF₂CH₂ OCF═CF₂ Homopolymer

A 400 mL Hastelloy pressure vessel was charged with 2.0 g of ahomopolymer of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂ (prepared as described inExample 10 with an inherent viscosity of 0.12) and 150 mL of1,1,2-trichlorotrifluoroethane. The vessel was closed, cooled with dryice and charged with 12 g of chlorine. The vessel contents were heatedto 90° C. for 2 hr and 125° C. for 18 hr. The vessel was cooled andvented to atmospheric pressure. The light yellow solution wasconcentrated under vacuum to 1.81 g of solid. Its proton NMR spectrum in1,1,2-trichlorotrifluoroethane showed absorption at 4.5 ppm for the--OCH₂ -- group and a small peak at 4.85 ppm assigned to an --SCH₂ Climpurity. There was no absorption detected for the SCH₃ group which ispresent in the starting polymer.

EXAMPLE 13 Conversion of the --SCH₃ Group to --SO₂ Cl in the CH₃ SCF₂CF₂ CH₂ OCF═CF₂ Homopolymer

A 210 mL Hastelloy® pressure vessel was charged with 5.0 g of thehomopolymer of CH₃ SCF₂ CF₂ CH₂ OCF═CF₂ (prepared as described inExample 10 with an inherent viscosity of 0.15) and 100 mL of carbontetrachloride. The vessel was closed, cooled with dry ice and chargedwith 15 g of chlorine. The vessel contents were heated to 125° C. for 18hr. The vessel was cooled and vented to atmospheric pressure. The clearlight yellow solution from the pressure vessel was bubbled with nitrogenfor a few minutes to remove excess chlorine. A proton NMR spectrum ofthe solution showed a peak at 4.42 ppm (--OCH₂ --) and the completeabsence of the CH₃ resonance of the starting polymer. ¹⁹ F NMR (δ, CCl₄)-93.7 (2F, CF₂ S), -113.0 (2F, backbone CF₂), -118.0 (2F, CH₂ CF₂), -130to -133.5 (1F).

About one-half of the above carbon tetrachloride solution was diluted to100 mL with carbon tetrachloride and transferred to a 500 mL creasedflask. Aliquat® 336 surfactant (0.1 g) (Janssen Chimica) was added,followed by 100 mL of an aqueous sodium hypochlorite solution. Thismixture was stirred vigorously for 1 hour at room temperature and for 3hours at 40° C. After standing overnight, the mixture was filtered andthe solid polymer was dried at 100° C. and 0.05 mm giving 2.61 g ofwhite solid which was insoluble in carbon tetrachloride and1,1,2-trichlorotrifluoroethane. An infrared spectrum of the solid showeda strong band at 1415 cm⁻¹ confirming presence of the SO₂ Cl group.

What is claimed is:
 1. A polymer consisting essentially of the repeatunits ##STR5## wherein: Q is --SO₃ M, --SCl, --SO₂ Cl or --SR¹ ;n is aninteger of 1 to 10; M is hydrogen, an alkali metal cation or an ammoniumion; and R¹ is an alkyl group containing 1 to 10 carbon atoms; andprovided that the molar ratio of (I):(II) is 0:100 to about 99:1.
 2. Thepolymer as recited in claim 1 wherein n is
 1. 3. The polymer as recitedin claim 1 wherein Q is SO₃ M.
 4. The polymer as recited in claim 2wherein Q is SO₃ M.
 5. The polymer as recited in claim 3 wherein M ishydrogen.
 6. The polymer as recited in claim 1 wherein the molar ratioof (I):(II) is 10:1 to about 1:10.
 7. The process of using the polymeras recited in claim 3 as an ion exchange resin.
 8. The polymer asrecited in claim 3 wherein M is hydrogen.
 9. The process of using thepolymer as recited in claim 8 as an acid catalyst.
 10. The polymer asrecited in claim 1 wherein the ratio of (I):(II) is 0:100.
 11. An ionexchange resin comprising the polymer recited in claim
 3. 12. An acidcatalyst comprising the polymer recited in claim 8.